CN1293184A - Process and equipment for preparing aromatic carboxylicacid - Google Patents
Process and equipment for preparing aromatic carboxylicacid Download PDFInfo
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- CN1293184A CN1293184A CN 00125752 CN00125752A CN1293184A CN 1293184 A CN1293184 A CN 1293184A CN 00125752 CN00125752 CN 00125752 CN 00125752 A CN00125752 A CN 00125752A CN 1293184 A CN1293184 A CN 1293184A
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Abstract
A process and equipment for preparing aromatic carboxylic acid features that the reaction takes place in a flow form approaching the piston flow in reactor to increase the speed and transform rate of oxidizing paraphenyldimethylene or metaphenyldimethylene into terephthalic acid or metaphthali acid. Its transform rate can reach 99.5%.
Description
The present invention relates to the production method of aromatic carboxylic acid, relate in particular to the production production method of terephthalic acid (PTA) and m-phthalic acid (PIA).
Terephthalic acid and m-phthalic acid are important chemical material, and the whole world has the industrial scale more than 1,000 ten thousand tons/year, are mainly used in to produce polyester (PET) and resin.
The industrialized preparing process of aromatic carboxylic acid is corresponding methylbenzene, such as p-Xylol, m-xylene, under acetate solvate and Co-Mn-Br catalyst action, by airborne oxygen oxidation, generate the paste-like solution of terephthalic acid or m-phthalic acid, through overcooling, crystallization, separation, washing, separate the coarse isophthalic acid that obtains containing the crude terephthalic acid of 4-carboxyl benzaldehyde (4-CBA) or contain 3-carboxyl benzaldehyde (3-CBA) again.Aldehyde type impurities dissolves through high-temperature water, hydrofining under the Pd/C catalyst action again, and recrystallization obtains purified terephthalic acid or m-phthalic acid.
In whole technological process, the oxidation reaction process of p-Xylol or m-xylene is the key of producing, and oxidation reactor is the core apparatus of producing.
At present, industrialized terephthalic acid or m-phthalic acid production method are to carry out at the tank reactor of being with stirring rake, as described in patent US2962361 and US3092658.In stirred reactor, agitator generally is made up of 2-3 group stirring rake, and the effect of lower floor's oar is solid terephthalic acid or the m-phthalic acid that suspension reaction generates, and prevents that the bottom sedimentation from scabbing, the middle part prevents the coalescence of gas bubbler or/and the top stirring rake is used to disperse bubble.In large-scale industrial installation, the aspect ratio of reactor is very little, is about 1.2-1.6, and whole reactor is exactly a continuous stir reactor basically, and this production method has influenced W-response speed.
In addition, patent EP0618186A1 discloses another kind of reactor, and the stirring rake of this reactor is the bottom of the equipment of being contained in, and advances a stirred reactor under being called, and gas directly enters from the bottom, and its flow state also is equivalent to a continuous stir reactor basically.Therefore also exist and patent US.2962361 and the same defective of patent US.3092658.
The object of the present invention is to provide a kind of terephthalic acid or the method for m-phthalic acid and device of realizing described method in tower reactor, produced, the low defective of existing speed of reaction when producing terephthalic acid or m-phthalic acid to overcome above-mentioned continuous stir reactor.
Design of the present invention is such: according to Study on Kinetics, the mechanism of dimethylbenzene oxidation reaction has mainly experienced methyl and become the aldehyde process of souring again, and is as follows:
Wherein, reaction (1) and (2) is the fastest, and in reaction product, the content of p-Xylol and p-tolyl aldehyde is very low, and the speed of latter two reaction (3) and (4) is lower, and reaction (3) is the controlled step of entire reaction course.Therefore, the product selectivity of dimethylbenzene oxidation process is very high, and the major objective of reactor design is to strengthen speed of response, improves transformation efficiency.
This is a typical gas-liquid-solid phase reaction, reaction simultaneous solvent evaporation and product crystallization, and the influence of oxygen transmittance process must be considered.But result of study and practical experience show that the influence of oxygen transmittance process is very little.In addition, owing to be that heat is removed in solvent evaporation, the influence of heat transfer process is also very little.Therefore, this heterogeneous reaction process is a process that mainly is subjected to reaction kinetics control, and decision speed of reaction key is reactant concn and temperature of reaction.
Reactant concn is generally determined by the mass ratio of a solvent/terephthaldehyde or a benzene diformazan, is 3-5, generally gets 4, and mainly by the flowing property decision of product slip, the leeway of practical adjustments is little for the amplitude of variation.Improve temperature of reaction and be the effective measure that improve speed of response, still, improve temperature will make terephthalic acid and solvent acetic acid decarboxylation side reaction, and acetic acid oxidation side reaction increases.At present, oxidation is produced in the technology of terephthalic acid or m-phthalic acid, and temperature of reaction is between 185-205 ℃, mainly about 190 ℃.
Therefore, on the prior art basis, from reacting the angle of own and transmittance process, the measure that improves speed of response is not very effective.
For this reason, the present invention is from another angle, promptly from the angle of the flow-pattern that changes reactor, with the flow-pattern near a continuous stir reactor of the prior art, change into form near plug flow reactor, improve speed and transformation efficiency that a terephthaldehyde or a benzene dimethoxy turn to terephthalic acid or m-phthalic acid, can significantly strengthen production intensity.
Realize that purpose method of the present invention comprises the steps:
1. oxidation reaction process, p-Xylol or m-xylene, acetate solvate and CATALYST Co-Mn-Br are provided with the tower reactor of transverse wall and midfeather from the bottom introducing together, transverse wall and midfeather are sieve tray, p-Xylol or m-xylene are generated the paste-like solution of terephthalic acid or m-phthalic acid by airborne oxygen oxidation.Owing to be provided with transverse wall and midfeather in the tower reactor, the formed space of each transverse wall and midfeather is equivalent to a little perfectly mixed reactor, make paste-like solution flow to another little perfectly mixed reactor from a little perfectly mixed reactor, with the flow-pattern of integral body near piston flow, at the bottom of tower, flow, flow out from the cat head reacting product outlet at last to cat head;
2. the heat of reaction generation is vaporized acetate solvate, enters follow-up condenser, and solvent is condensed, and partial solvent enters reactor by trim the top of column, and part enters reactor after converging with reaction raw materials again, recycles;
3. separation and purification process, the reaction product behind the condensing solvent is sent to follow-up separation and purification operation, can adopt conventional method to carry out separation and purification.
Other processing condition of above-mentioned reaction process are same as the prior art, and catalyzer can adopt catalyzer same as the prior art, and its prescription is: Co
2+=150-300ppm (wt), Mn
2+/ Co
2+=0.5-2.0, Br
-/ (Mn
2++ Co
2+)=0.6-1.0.Batching all adopts Co (AC)
24H
2O, Mn (AC)
24H
2O and HBr;
The air feed amount generally is controlled at the O in the reaction end gas
2Content is 2-3%.Reaction pressure is 1-2Mpa, and temperature of reaction is 185-205 ℃;
In the reactor, the water-content of reaction mass also will be controlled between the 5-8% (wt).
But for making the flow-pattern of reaction mass maintenance near piston flow, whole tower reactor should be equivalent to 3～6 placed in-line little perfectly mixed reactors, and the aspect ratio of tower reactor is 2～12.
Be used to realize that the device of the object of the invention comprises:
A tower reactor and at least one condenser.
Be provided with sparger, following sparger, a plurality of transverse wall and a plurality of midfeather in the said tower reactor, transverse wall and midfeather are sieve tray.
Said upward sparger is arranged on the top of tower body, and is connected with the phegma inlet;
Said sparger down is arranged on the bottom of tower body, and is connected with the feed(raw material)inlet;
Said transverse wall and midfeather are sieve tray, are arranged in the cavity between sparger and the following sparger.
Said transverse wall is separated into a plurality of spaces from top to bottom with reactor, and each space promptly is equivalent to a little perfectly mixed reactor, whole reactor is in series by a plurality of little perfectly mixed reactors, reaction mass is flowed with the form near piston flow in reactor, thereby can improve W-response efficient;
Said midfeather is separated into a plurality of zones with the cross section of reactor, with the height/footpath of improving the reactor regional area than, make the flow-pattern of reaction mass in tower reactor more near piston flow.
The feed(raw material)inlet is located at reactor lower part, and reacting product outlet, solvent outlet and solvent refluxing mouth are located at reactor top;
Said condenser can adopt conventional condenser, be used for the cooling with reaction product, and the acetate solvate that will vaporize is condensed into liquid; Said condenser is connected with tower reactor by pipeline.
Air, p-Xylol or m-xylene, acetate solvate and Co-Mn-Br catalyzer enter reactor by the feed(raw material)inlet of the bottom of reactor by following sparger, p-Xylol or m-xylene are under the effect of Co-Mn-Br catalyzer, by airborne molecular oxygen oxidation, generation is to benzene or m-phthalic acid, and emit a large amount of heats, liberated heat is shifted out by solvent evaporation;
The solvent of evaporation by reactor top solvent outlet outflow reactor, enters condenser with the remaining air of reaction, and solvent is condensed, and partial solvent enters reactor by the last sparger backflow of cat head, and part enters reactor after converging with reaction raw materials again.
Reaction product is sent to follow-up separation and purification operation, can adopt conventional method to carry out separation and purification.
Below will the present invention is further illustrated by accompanying drawing.
Fig. 1 is a process flow sheet of the present invention.
Fig. 2 is the structure of reactor synoptic diagram.
Fig. 3 is a bar shaped transverse wall synoptic diagram.
As seen from Figure 1, the said method of the present invention comprises the steps:
1. oxidation reaction process, p-Xylol or m-xylene, acetate solvate and CATALYST Co-Mn-Br together are provided with the tower reactor 1 of transverse wall and midfeather from the bottom introducing, generate the paste-like solution of terephthalic acid or m-phthalic acid, paste-like solution flows to cat head at the bottom of tower with the flow-pattern of single-piece piston stream, flow rate is 1～10 mm/second, flow out from the cat head reacting product outlet at last, be sent to follow-up separation and purification operation, can adopt conventional method to carry out separation and purification;
2. the heat of reaction generation is vaporized acetate solvate, enters follow-up condenser 2, and solvent is condensed, and partial solvent enters reactor 1 by trim the top of column, and part enters reactor after converging with reaction raw materials again, recycles;
Condenser can be provided with three grades, but the steam of first step condenser by-product 0.4-0.5Mpa, but the steam of second stage condenser 22 by-product 0.2Mpa, third stage condenser 23 adopts water condensation.Water-content in three grades of phlegmas increases successively, and third stage phlegma major part is gone to follow-up workshop section.The phlegma of I and II condenser all is back in the reactor.The air that goes out condenser is through purifying back emptying.
As seen from Figure 2, said tower reactor comprises housing 4, last sparger 5, following sparger 3, a plurality of transverse wall 8 and a plurality of midfeather 7, and transverse wall 8 and midfeather 7 are provided with sieve aperture 10;
Said transverse wall 8 and midfeather 7 are separated into a plurality of spaces from top to bottom with reactor, and each space promptly is equivalent to a little perfectly mixed reactor, and whole reactor is in series by a plurality of little perfectly mixed reactors.
The aspect ratio of tower reactor is 5～12;
The equivalent aspect ratio of each little perfectly mixed reactor is 0.5～2.0;
Said equivalent aspect ratio is defined as:
Little perfectly mixed reactor height/little perfectly mixed reactor equivalent diameter;
Little perfectly mixed reactor equivalent diameter=little perfectly mixed reactor girth/pi.
Said upward sparger 5 is arranged on the top of tower body, and is connected with phegma inlet 6;
Said sparger 3 down is arranged on the bottom of tower body, and is connected with feed(raw material)inlet 9;
Solvent vapo(u)r outlet 11 is arranged on the top of reactor, and reacting product outlet 12 is arranged on the top of reactor;
Last sparger 5 can adopt multiple structure, and the present invention does not limit especially, and nozzle preferably makes progress, and the caliber size of nozzle is suitable, and will prevent to stop up, because the steam of evaporation and air may the entrained solids feed liquid enter condenser.Generally speaking, nozzle diameter 5-30mm is preferably between the 8-15mm.The top phegma upwards sprays through last sparger 5, not only can reach mixed uniformly purpose, but also can prevent reactor head slip knot wall.
Following sparger 3 also can adopt multiple structure, and the present invention does not limit especially yet, preferably adopts the endless tube sparger, on endless tube, evenly has downward nozzle, and the arrangement requirement gas and the spouting of liquid of nozzle have certain angle.In addition, nozzle is cross arrangement on endless tube, and one outwards, and one inwardly, all becomes 30-45 ° of degree angle with level and vertical direction, like this, can guarantee that the whole reactor bottom evenly is covered with one deck air film.
Transverse wall 8 and midfeather 7 can adopt round-hole punched plate, and square-netting screen can also adopt the bar shaped sieve plate, and the present invention does not do special restriction.But, in the present invention, sieve plate is not in order to strengthen mass transfer, but the back-mixing of limit fluid, and restriction gas (vapour) bubble, prevent coalescence and bumping.In addition, because gas (vapour) body stream is coflow with liquid flow, also needn't consider the problem of liquid flooding.Simple in view of the design and the making of bar shaped sieve plate, can preferably adopt.Bar shaped transverse wall 8 as shown in Figure 3, whole dividing plate is assembled by grizzly bar 13.The design considerations of bar shaped dividing plate is a percentage of open area, is generally 10-40%, and suitable scope is 20-30%.The width of grizzly bar 13 is 5-50mm, and reactor diameter is little, and grizzly bar 13 width can be smaller, otherwise reactor diameter is big, and grizzly bar 13 width can be greatly.For a common terephthaldehyde or a benzene diformazan oxidation reactor, suitable grizzly bar 13 width are 10-30mm.
At reactor bottom, the liquids and gases that enter can form sufficient, downward injection gas and liquid stream, have not only guaranteed sufficient feed liquid mixing, and solid product is effectively suspended, and scab bottom preventing.In addition, because reaction mass is to enter in the bottom, the content of product terephthalic acid or m-phthalic acid increases from bottom to top, and content is minimum in the bottom.Especially, in the bottom, the reaction that p xylene oxidation is a p-methylbenzoic acid takes place mainly, or the reaction that m-xylene is oxidized to m-methyl benzoic acid takes place, the solid materials content of reactor bottom can keep very low, and the possibility of deposition of solids is very little.Adopt the said method and apparatus of the present invention, transformation efficiency can reach 99.5%.Therefore, special PTA that provides of the present invention or PIA production method and device are of great value for the transformation of prior art.
The process of m-xylene oxidation system m-phthalic acid is equivalent to produce per year 50,000 tons of smart m-phthalic acids.Reactor diameter is 1.8m, and height is 9.0m.5 transverse walls and 2 midfeathers are set in the reactor altogether, adopt the bar shaped sieve plate, the spacing of transverse wall 5 is for l.0m, and percentage of open area is 25%, and the width of grizzly bar 13 is 10mm.
The condition of reaction is: m-xylene charging=4.0 ton/h, air capacity=14300Nm
3/ h, T=191 ℃, P=1.22Mpa, solvent ratio=3.5, Co
2+=200ppm, Mn/Co=2, Br/ (Co+Mn)=0.8.
Air, m-xylene (be dissolved in the acetate solvate, and contain catalyzer) enter reactor from reactor bottom, behind gas, liquid distributor, are uniformly distributed in the whole cross section of reactor.Slip flows out from reactor top, reacts the solvent of remaining air and evaporation and discharges from the top, enters three grades of condensers again.Condensation reflux liquid is divided into two portions, and wherein about 20% enters the top, and 80% enters the bottom.
Reaction result is, in the outlet slip, m-xylene content is 0.025% (wt), and m-methyl benzoic acid is 0.042% (wt), and the 3-carboxyl benzaldehyde is 0.019% (wt), and transformation efficiency is 99.75%.
The process of p xylene oxidation system terephthalic acid is equivalent to produce per year 600,000 tons of pure terephthalic acids.Reactor diameter is 6.3m, and height is 9.0m.Be provided with 6 transverse walls and 5 midfeathers in the reactor altogether, adopt the bar shaped sieve plate, percentage of open area is 30%, and the width of grizzly bar 13 is 20mm, and spacing is 1.2m.
The condition of reaction is identical with embodiment 1.
Air, terephthaldehyde's (be dissolved in the acetate solvate, and contain catalyzer) enter reactor from reactor bottom, behind gas, liquid distributor, are uniformly distributed in the whole cross section of reactor.Slip flows out from reactor top, reacts the solvent of remaining air and evaporation and discharges from the top, enters three grades of condensers again.Condensation reflux liquid is divided into two portions, and wherein about 20% enters the top, and 80% enters the bottom.
Reaction result is, in the outlet slip, terephthaldehyde's content is 0.02% (wt), and p-methylbenzoic acid is 0.032% (wt), and the 4-carboxyl benzaldehyde is 0.102% (wt), and transformation efficiency is 99.8%.
Claims (8)
1. method of producing aromatic carboxylic acid is to be raw material with p-Xylol or m-xylene, carries out under the processing condition of routine, it is characterized in that this method comprises:
1. p-Xylol or m-xylene, acetic acid and catalyzer together are provided with the tower reactor (1) of transverse wall and midfeather from the bottom introducing, the terephthalic acid that generates or the paste-like solution of m-phthalic acid flow to cat head at the bottom of tower, flow out from the cat head reacting product outlet at last;
2. the acetic acid of being vaporized by reaction heat enters condenser (2) condensation, and part acetic acid enters reactor (1) by trim the top of column, and part enters reactor (1) after converging with reaction raw materials again.
2. the method for claim 1 is characterized in that, paste-like solution is 1～10 mm/second to cat head mobile flow rate at the bottom of the tower.
3. device that is used to realize the method for claim 1 or 2 is characterized in that this device comprises:
A tower reactor and at least one condenser;
Said tower reactor comprises housing (4), last sparger (5), following sparger (3), a plurality of transverse wall (8) and midfeather (7) that is provided with sieve aperture (10);
Said transverse wall (8) and midfeather (7) are separated into how little perfectly mixed reactor from top to bottom with reactor;
Said upward sparger (5) is arranged on the top of tower body, and is connected with phegma inlet (6);
Said sparger (3) down is arranged on the bottom of tower body, and is connected with feed(raw material)inlet (9);
Solvent vapo(u)r outlet (11) is arranged on the top of reactor, and reacting product outlet (12) is arranged on the top of reactor;
Reactor is connected by pipeline with condenser.
4. device as claimed in claim 3 is characterized in that, the aspect ratio of tower reactor is 2～12; The equivalent aspect ratio of little perfectly mixed reactor is 0.5～2.0.
5. device as claimed in claim 3 is characterized in that, last sparger (5) is provided with nozzle upwards, and following sparger (3) is provided with downward nozzle.
6. device as claimed in claim 3 is characterized in that, transverse wall (8) and midfeather (7) are round-hole punched plate, square-netting screen or bar shaped sieve plate.
7. device as claimed in claim 6 is characterized in that, the percentage of open area of transverse wall (8) and midfeather (7) is 10-40%.
8. device as claimed in claim 7 is characterized in that, the percentage of open area of transverse wall (8) and midfeather (7) is 20-30%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN00125752A CN1097577C (en) | 2000-10-24 | 2000-10-24 | Process and equipment for preparing aromatic carboxylicacid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN00125752A CN1097577C (en) | 2000-10-24 | 2000-10-24 | Process and equipment for preparing aromatic carboxylicacid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1293184A true CN1293184A (en) | 2001-05-02 |
| CN1097577C CN1097577C (en) | 2003-01-01 |
Family
ID=4591536
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN00125752A Expired - Fee Related CN1097577C (en) | 2000-10-24 | 2000-10-24 | Process and equipment for preparing aromatic carboxylicacid |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100368370C (en) * | 2006-03-29 | 2008-02-13 | 中国石化仪征化纤股份有限公司 | Recovery system of suspended substance in para dimethyl benzene oxidation mother liquor |
| CN102869439A (en) * | 2010-04-30 | 2013-01-09 | 塞彭公司 | Reactor for effecting gas-liquid biphasic reactions |
| JP2016528228A (en) * | 2013-07-31 | 2016-09-15 | ユーオーピー エルエルシー | Method and system for separating streams to provide a transalkylation feed stream in an aromatic compound facility |
| CN106237966A (en) * | 2016-08-23 | 2016-12-21 | 南京大学 | The reactor of aromatic aldehyde is produced for the oxidation of toluene class material |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3198711B2 (en) * | 1993-03-30 | 2001-08-13 | 三井化学株式会社 | Method and apparatus for producing terephthalic acid |
| US5919977A (en) * | 1997-02-20 | 1999-07-06 | Mitsui Chemicals, Inc. | Process for producing aromatic carboxylic acid and apparatus therefor |
-
2000
- 2000-10-24 CN CN00125752A patent/CN1097577C/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100368370C (en) * | 2006-03-29 | 2008-02-13 | 中国石化仪征化纤股份有限公司 | Recovery system of suspended substance in para dimethyl benzene oxidation mother liquor |
| CN102869439A (en) * | 2010-04-30 | 2013-01-09 | 塞彭公司 | Reactor for effecting gas-liquid biphasic reactions |
| JP2016528228A (en) * | 2013-07-31 | 2016-09-15 | ユーオーピー エルエルシー | Method and system for separating streams to provide a transalkylation feed stream in an aromatic compound facility |
| CN106237966A (en) * | 2016-08-23 | 2016-12-21 | 南京大学 | The reactor of aromatic aldehyde is produced for the oxidation of toluene class material |
| CN106237966B (en) * | 2016-08-23 | 2018-11-09 | 南京大学 | The reactor of production aromatic aldehyde is aoxidized for toluene substance |
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|---|---|
| CN1097577C (en) | 2003-01-01 |
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